Liquid metering pump



Get. 21, 1969 w. D. HENDERSON 3,473,697

LIQUID METERING PUMP Filed Nov. 22, 1967 2 Sheets-Sheet l HQ METERINGPUMP William Dick Henderson, 2328 Henderson Highway,

Winnipeg, Manitoba, Canada Filed Nov. 22, 1967, Ser. No. 685,128 Claimspriority, application Canada, Nov. 24, 1966, 976,323 Int. Cl. B6711 /12US. Cl. 222--75 3 Claims ABSTRACT OF TIE DISCLOSURE A liquid pump isdescribed consisting of a cylinder, a piston in the cylinder and aplurality of liquid introduction lines which may be selectedindividually to lead liquid under pressure to one side of the piston. Acompressed gas can be led to the other side of the piston for forcingthe piston to eject the liquid through a discharge line. The gas spacecan also be vented to allow more liquid to enter and force up thepiston. Shut oiT valves in the liquid introduction lines enable one orother of the liquids to be chosen for pumping at will.

This invention relates to an apparatus for pumping liquids and hasparticular reference to apparatus for receiving liquids from severalindependent supplies and delivering them without intercontamination toat using site.

In automobile service stations premium product oils are almostuniversally provided in sealed cans. For the lower grades of oil,several hand pumps are provided, one for each viscosity of oil, mountedover the drum containing the particular oil to which the pump relates.With the premium oil there is additional cost to the consumer because oftthe extra labour involved in sealing the oil into cans and distributingthem as such. Some of the product is also lost in pouring the oil fromthe can into the automobile since it is virtually imposible to drain acan with any measure of efliciency in the short time available. In thesecond case, where oil is drawn from drums it is pumped into a measuringjug and from there dispensed into the automobile oil filler opening. Themeasure is open to the atmosphere and can become contaminated with dustand water. It is also difiicult to drain the measure effectively in thetime interval permitted.

Improvements in the method of distributing oil have been described andclaimed in my United States Patent 3,186,597 and the present inventionfind particular application as a pump in association with the dispensingsystem of that patent.

The present invention may also be employed with advantage in the liquidproportioning system disclosed and claimed in my United States Patent3,283,957 in which it ensures that additive is alway available under achosen pressure for metering into a second liquid.

The present invention overcomes dimculties experienced in the prior artfor the feeding of multiple liquids by allowing a choice between one orother liquid to be made at any time and it has the advantage ofemploying compressed gas as a driving fluid and can therefore be madeentirely safe in the handling of inflammable liquids.

More particularly in accordance with the present invention there isprovided a liquid pump which comprises a cylinder, a piston in saidcylinder, a plurality of liquid introduction lines for leading liquidunder pressure into a first space defined by said cylinder on one sideof said piston, means for feeding gas under pressure into a second spacedefined by said cylinder on the other side of said piston, valve meansfor alternately permitting gas feed to and venting of the second space,a liquid shut off means in each of said lines, a check valve in each ofsaid lines nited States Patent 0 3,473,697 Patented Oct. 21, 1969closely adjacent said first space, and means for feeding liquid fromsaid first space under pressure of said gas in said second space.

The invention will now be described with reference to the accompanyingdrawings in which:

FIGURE 1 shows a perspective view of one embodiment of the inventionconnection up to receive oil from a number of sources and to dischargeit either for filling an oil dispensing unit or through a hose,

FIGURE 2 shows an enlarged view of the base portion of the pump ofFIGURE 1 sectioned along line 2-2,

FIGURE 3 shows further details of the pump of FIG- URES 1 and 2, with anarrangement to prevent sticking of the piston,

FIGURE 4 shows an automatic system for the invention,

FIGURE 5 shows an alternative embodiment of the invention withelectrically operated valve means, and

FIGURE 6 shows an alternative embodiment without piston and cylinderoperation.

With reference to FIGURE 1 the pump of the invention comprises acylinder 1 preferably of tough transparent material such as an acrylicplastic to which are fastened two end plates 2 and 3 suitably by meansof bolt 4 carrying a nut 5. A piston 6 is received within the cylinderand is slidably sealed to it by an O-ring 7. The piston is also slidablysealed to the bolt 4 by means of an O-ring (not shown) within the hole 8through which the bolt 4 passes. The space 10 formed beneath the pistoncan receive liquid under pressure through any one of the multiplicity ofpipes 11. Only three pipes are shown, but there could be as many asrequired subject to space limitations. The liquid from any one of thepipes 11 enters the space 10 through a shut-off valve 35 and a checkvalve 36 and thence through the ports 12. Liquid can leave space 10through either the discharge port 15 leading to hose 16 or throughnozzle 17 adapted for coupling to dispenser 18 such as described in myPatent 3,186,597.

Air can be led to the space 20 above piston 6 through a pressure line 21and a three-way valve 22. In the first position of the valve 22 the airpasses through the valve and down pipe 23 through plate 3, and into thespace 20. In the second position of the valve the air within space 20can pass back out through pipe 23 and be vented at 24.

Let use now assume that a liquid is present in drum 30 (not drawn toscale) which includes a dip tube 31 and a space 32 above the liquidwhich can be pressurized by air introduced through a small check valve33. Alternatively the drum 30 may be arranged at a higher level thancylinder 1 and then can supply liquid under gravity. Dip tube 31 wouldbe replaced by a pipe leading from the bottom of drum 30 in the secondinstance.

Returning to FIGURE 1 let us assume that the handle 25 of three-wayvalve 22 is in the position to vent the space 20 and that shut-off valve35 is open. The air pressure in space 32 then urges the liquid 34 up thedip tube 31 through the opened shut-off valve 35 through a check valve36 and into space 10 through port 12. The liquid entering the space 10pushes the piston 6 upwards exhausting the air in space 20. When thepiston 6 reaches the top of its travel the handle 25 of valve 22 isthrown into the position to allow air under pressure to arrive throughpipe 21. liquid can then be withdrawn either by opening valve 40 toallow it to flow out through hose 16 or by inserting the oil dispenser18 into the nozzle 17. As explained in my Patent 3,186,597 the couplingof the male nozzle 41 with the female nozzle 17 allows dispenser 18 tofill under the control of the handle 42. The dispenser 18 is thenremoved and by raising handle 42 liquid Within the dispenser can beejected from nozzle 41. This is all described in that patent.

If the capacity of cylinder 1 is made equal to that of the dispenser 18,then one full charge from the apparatus of FIGURE 1 will fill dispenser18 and the piston 6 will be at the bottom of its travel when dispenser18 is filled. Another liquid can now be led into cylinder 1 if desiredby closing valve by means of handle 44 and opening one of the othervalves 35 or 35" by utrning the handles 45 or 46.

The structure of the end plate 2 can be seen in greater detail withreference to FIGURE 2. The check valves 36 should be as close aspossible to the discharge port 12 with which they connect. This ensuresthat contamination of one liquid with another is as small as possiblewhen the-delivery of one liquid is changed to another. The check valves36 should be provided with fairly weak springs so that they are easilyopened by the fiow of liquid from the respective supply pipe 11 eventhrough the liquid may be supplied under quite a low pressure. Thepassages to the discharge hose and nozzle should be as small as possible(consistent with having adequate flow) to avoid contamination whenchanging from one liquid to another. The end plate 2 and the end plate 3(not shown) are formed with grooves into which the cylinder 1 isreceived. This ensures that an adequate seal between the cylinder andend plate exists when the assembly is bolted up. If desired, a sealingstrip may be laid down in the groove 50' to improve the seal. In orderthat there should be no leakage around the bolt 4 passing through theend plates, a fibre washer is placed under nut 5 and the head of thebolt. Alternatively each end plate may be formed with a groove withinthe hole 52 for the bolt which groove receives an O-ring 53 for sealingagainst the bolt shank 4 (see FIGURE 3).

An alternative embodiment of this invention is shown in FIGURE 3 inwhich the end plate 3 is fed not from the side but from beneath as at60. A hose 61 controlled by valve 62 is received in the passage 60. Acheck valve 65 supported within space 60 by spring 66 has its head 67very closely adjacent the top side 69 of the end plate 3. This procedureensures an absolute minimum of contamination of one liquid by anotherwithin cylinder 1. In this drawing of FIGURE 3 the seal 68 containedwithin the hole 8 of the piston 6 is shown. In circumstances where thepiston 6 is a tight fit on the cylinder 1 and particularly after thepump has been idle for a long period it may be desirable to include anejector 70 for nudging the piston if it sticks at the bottom of itstravel. The ejector 70 is sealed within a passage 71 by means of a smallsealing O-ring 72. The ejector 70 is suitably operated by means of alever 73 fulcrumed at 74 with a handle 75.

The apparatus may also be made to operate automatically by means of asuitable assembly such as shown in FIGURE 4. A pneumatically operatingdiaphragm control is connected to alter the position of the three-wayvalve 22. While the piston is descending, air pressure from pipe 21 iswithin the space 20. When the piston reaches the bottom of its travel itencounters a push rod 91 which opens a valve 92 feeding pressurized airfrom pipe 93 through pipe 94 to operate control 90 and switch thethree-way valve into the position which vents the space 20. As thepiston 6 then rises and reaches the top of its travel it will encountera push rod which operates a valve 101 and allows air from a pipe 103 topass through pipe 102 and reverse the position of control 90. Thisalters the position of the three-way valve 22 and pressurizes the space20 above the piston 6. In order to prevent any build up of pressure inthe control 90 each of its sides may be slowly bled so that by the timethe piston 6 reaches the top of its travel the side which has beenpressurized through pipe 94 has reached approximately atmosphericpressure. Other mechanisms will be apparent to those skilled in the art.During the descent of piston 6 the side pressurized through pipe 102will in its turn bleed down to atmospheric pressure. It will beunderstood by those skilled in their art that the valves 101 and 92 maybe replaced by limited movement switches and the control of '90 be madeelectric. The push rods 91 and 160 are suitably sealed for slidingmovement by respective O-rings 104 and 105. The advantage of havingautomatic operation for the pump is that a continuous supply of liquidcan be drawn from it and this is particularly useful when the dischargehose 16 is being used or when the additive system of Patent 3,283,957 isemployed.

In the prototype it ha been found that a pressure of 3 to 7 p.s.i.g. hasbeen satisfactory for the liquid led into ports 12. A pressure in line21 of 100 p.s.i.g. would deliver oil of ten to thirty SAE viscosity at arate of 2 to 2 /2 gallons per minute.

A further way of making the device of the invention operateautomatically is to adopt the procedure shown in FIGURE 5. Here thethree-way valve 22 of FIGURE 1 is replaced by an electrically operatedthree-way valve 110. The. valve is controlled by a solenoid 111 whichconnects the pressure line 21 to the down pipe 23 or the vent 24 to thepipe 23. The setting of the valve is controlled by a switch 112 mountedon the nozzle 113 where the liquid is to be discharged. Switch 112 isconnected through a plug 114 to the solenoid 111 fed in turn from apower supply 115. This arrangement has the advantage over thearrangement of FIGURE 4 that recharging of the cylinder 1 is undercontrol at the discharge nozzle which may be held open until fiow ofliquid ceases before the switch 112 is thrown for recharging. Thisensures that the piston 6 in the cylinder 1 will come to rest at thebottom on the cylinder before the cylinder is recharged. If desired inspecial cases, a control valve 116 on the nozzle 113 and switch 112 maybe interconnected as indicated at 118 so that when the nozzle control isreleased the cylinder 1 refills.

An alternative way of carrying out the invention is shown in FIGURE 6and is especially useful for dispensing oil or antifreeze. In this, acylinder with floating piston is no longer employed and is re laced by apressure tank 120. There is a dip tube 121 passing into the tank whichfeeds a discharge hose at nozzle 128. The tank is filled through a pipe125 via a check valve 126 from liquid contained in a storage vessel 127arranged above the tank 120. A thin pipe 130 rises from the top of thetank 120 through a vapour condenser 131 if required.

' to a three-way valve 132. This valve vents through a pipe 135connected with an air blast operated counter 136 to a vent 137 which forconvenience can be directed into and loosely fit in opening 135 in thetop of the vessel 127. Pressurized air can be led in through pipe 140.

The operation of this arrangement is as follows: the three-way valve 132is connected to release any pressure in tank 120 connecting pipe 130 tothe vent pipe 135. Liquid now flows by gravity into the pressure tank120 and it will continue to do so until the liquid level rises in thetube 130 up to that of liquid in the vessel 127. The valve 132 is nowreversed and pressurized air is fed from pipe 140 through the vaporcondenser 131, if present, and into the pipe 130. Tube 130 is of smalldiameter but if extreme accuracy is required the pipe may be transparentand a mark made on it. The level of liquid can then be brought to thismark by reversing valve 132 when the mark is reached. A level sensitiveswitch may also be employed instead, for instance, to detect thepresence of the liquid in tube 130 at the correct height. If the handle141 on the nozzle is now opened, liquid will be forced through thedischarge tube 123 until pressure tank 120 is empty. The arrival of airwill inform the attendant that tank 120 is empty. It can now berecharged by reversing the position of valve 132. During this reversalair from the tank 120, and air in pipe 130 passes to the vent 137through the counter 136. The counter records the fact that valve 132 hasbeen reversed and that the tank is being recharged. Since the tank 120is filled at each reversal and drains to the bottom of the dip tube 121,a

known measure of liquid can be discharged from the tank.

I claim:

1. A liquid pump which comprises a cylinder, a piston in said cylinder,a plurality of liquid introduction lines for leading liquid underpressure into a first space defined by said cylinder on one side of saidpiston, means for feeding gas under pressure into a second space definedby said cylinder on the other side of said piston, valve means foralternately permitting gas feed to and venting of the second space, aliquid shut 01f means in each of said lines closely adjacent said firstspace, and means for feeding liquid from said first space under pressureof said gas in said second pace, an electrically operated solenoid,means connecting said solenoid and said alternate valve means foralternating of said valve means, a switch for said solenoid, said switchthereby being capable of operatively alternating said valve meansbetween its gas feed and gas venting position, a nozzle attached to saidliquid feeding means, means mounting said switch adjacent said nozzle,means for opening said nozzle, and means connecting said nozzle openingmeans and said switch, said valve means being in its gas ventingposition when said nozzle opening means is closed and in its gas feedposition when said nozzle opening means is open.

References Cited UNITED STATES PATENTS 1,327,990 1/1920 French 222-1362,271,022 1/1942 Nelson 10352 2,348,151 5/ 1944 Rotter et a1 222-752,692,704 10/1954 Benz 103-52. 2,774,364 12/1956 Brobeil 222-136 ROBERTB. REEVES, Primary Examiner H. S. LANE, Assistant Examiner US. Cl. X.R.

